First post, by Jed118
I have always wanted to build the "fastest" 386 with VESA. I got pretty close late last year when a friend dropped off a 3/486 EISA/VESA board, but as of now I have not been able to make it work with any 386 chip (the idea is to run my 40 MHz TI SXL in it with a VLB video card and SCSI) . This has been an ongoing project for the last 20 or so years, since I found the computer (originally an AM386DX/40) curbside back in 1999 or so. Now, if any of you ever had the task or dream or building a GT car from a base model (something I have done myself at least twice now), it is a time-consuming process, and usually luck at a junkyard or finding a parts car on line is involved. Lots of fabrication and reading of dealer/factory literature on the subject. You get close and... Then a "GT" machine shows up with a few missing parts.
I got this machine about a year ago on allegro.pl and it sat with my parents. I only knew that it booted to a German version of DOS as seen on the pictures of the auction. I finally had a chance to get to it after moving into my new place over 2 months ago.
Model 2168 type 245. This is the SLC with 16Kb L1 cache Blue Lightning. This one also came with 16 Mb RAM, an IIT FPU (33 MHz) and this one has 256k cache, although I read here that 128k will do fine because of the memory addressing beyond 16Mb takes a hit if it is exceeded.
It came pretty stripped out but it has a lot of integrated features. It seems I am not the first one to post one here, however I cannot find an easy way to get into the BIOS - the only way I found out how to was to unplug the floppy and hard drive, wait 2 minutes for the error code to come up, and the option appears to press F2. This is annoying, but at least I can get in.
Once in, I can set the multiplier - when I set it to 3x and leave the 25MHz jumper in, it boots OK. When I then switch it to 33MHz, it will not get past POST (I got a little further by removing the FPU - I will be replacing it with a 40MHz version and putting the 33MHz out of this one into a system that can use that speed) - the hard drive light stays on and that's it. So for now at 3x 25 MHz or 2x 33 MHz it is "stable" in the sense that it will boot and run NSSI. No further tests have been done.
I want to replace the video card - I so happen to just have an excellent Mach32 for the task. However, when I put it in, it beeps. I suppose there is a jumper somewhere? I've looked around on the net and can't find too much on the machine and even less on the chip. Any manuals out there? I found a generic multi-unit 400 page manual that mentions this, and also a setup diskette - I wonder if anyone has this one.
Perhaps my most important question - How would this compare to a 40 MHz SXL with 8k internal cache on a VLB motherboard? Is the external 16 bit addressing a concern? I plan to use it for games from about the time it was made - would this just be easier to tune up for that task rather than messing with the SXL (which is a true 32 bit chip - again though, does that make a difference for what I want?) The OS will be DOS (Probably DR-DOS if it will allow it, and Windows 3.11)
The only disadvantage is that it only has 2x 5.25 bays and I have 3 expansion devices of that size - since I'm going SCSI I can look out for an external CDROM enclosure I guess.
Either way, this is a unique system, and I seem to have a slightly more advanced IBM (W 95 keyboard and scroll mouse, ) peripherals, as well as a nice CRT to go with it. I think I'm going to like using it 😁